On Thu, 2009-10-22 at 08:18 +0200, Florian Haas wrote: > Steve, > > what has repeatedly come up is that RRP links don't auto-heal (see > thread: > http://oss.clusterlabs.org/pipermail/pacemaker/2009-May/001784.html), > and that passive mode RRP seems to not work at all (see thread: > https://lists.linux-foundation.org/pipermail/openais/2009-October/013095.html > -- this was also heavily discussed on IRC; the only approach that fixed > the issue was to change rrp_mode to active). Can you fill us in on the > progress on these issues? Thanks! > > Cheers, > Florian
Passive worked last time I tested, but its been awhile. Hardening redundant ring and making it more generally useful is on our community derived roadmap (targeted for 1.2.0). Please reference: ftp://ftp% 40corosync.org:downlo...@corosync.org/presentations/corosync-roadmap.pdf Regards -steve > > On 10/22/2009 06:14 AM, Steven Dake wrote: > > You can run with one NIC (and switch) but then your NIC and switch > > become a SPOF (single point of failure). Vehicles have a spare tire for > > a reason :) If a NIC fails it may be ok to switch a service to a > > different node. If a switch fails, The entire cluster becomes disabled > > until the switch returns to operation. > > > > Availability is a mathematical equation: > > > > A = MTTF / (MTTF+MTTR) > > > > Pacemaker improves availability (A) by reducing mean time to repair > > (MTTR) using failover while keeping the mean time to failure (MTTF) > > essentially the same (although it is generally a bit lower because of > > other components in the system required to introduce redundancy). > > Instead of a typical 1 machine MTTR of 4 hours under a typical SLA, MTTR > > may be 5-10 seconds or less (the time to failover the application and > > restart it). If MTTR is several days to service a switch, your > > availability may not meet your customer SLA obligations. When > > determining whether to use a redundant switch the risks vs cost have to > > be evaluated based upon your availability requirements. > > > > Regards > > -steve > _______________________________________________ Pacemaker mailing list Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker
